A conventional parking meter installed at a street side may be operated by dropping coins therein for timing purpose, which however may have the following drawbacks:
1. The car driver must prepare enough coins for dropping into the parking meter by estimating the fees based on an estimated total parking period. Otherwise, the driver may pay an extra fine if an unexpected overdue parking is caused.
2. The parking meters are juxtaposedly installed by a street, thereby possibly obstructing pedestrians or influencing the esthetic appearance of a city. A management cost for collecting the coins from the meters or a high maintenance cost for maintaining the meters may be consumed.
3. If it is necessary to set up several standards of parking fees with respect to different parking areas or zones, for instance, area A being 15 minutes of duration per parking unit (in terms of a specific amount of money) or area B being 30 minutes per parking unit, there must be provided many categories of parking meters preset with different time intervals with respect to the different areas, thereby resulting in an increase of their installation cost and also an increase of the driver's inconvenience since the driver must calculate the parking fees from area to area.
The present inventor has found such drawbacks of a conventional parking meter and invented the present microprocessor parking meter held internally in a car to overcome the aforementioned drawbacks.